On 19/10/15 17:41, Yasha Karant wrote:
> I posted the following to the
> 
>   * Board index <https://forums.virtualbox.org/index.php> *‹* General
>     <https://forums.virtualbox.org/viewforum.php?f=12> *‹* VirtualBox on Linux
>     Hosts <https://forums.virtualbox.org/viewforum.php?f=7>
> 
> a VirtualBox list similar to this SL list.  Interestingly, the post currently
> has 11 views but 0 responses.
> At this point, I am beginning to assume that VirtualBox has a significant
> limitation -- the typical VirtualBox NAT network driver
> that used to work with both an IEEE 802.3 and 802.11 ISP connection on the
> host no longer works with 802.11 on the host.
> 
> Evidently because of the large number of non-professional enthusiasts (typical
> end-users) who post to the VirtualBox lists, one uses an alias
> handle; this does not seem to be necessary on the SL list.
> 
> Assuming that VirtualBox cannot "virtualize" a 802.11 connection, is there any
> other virtualization system that is licensed for free (no longer the case
> with VMWare) that can use an existing virtual machine (e.g., vdi, vmdk files),
> that will support the guest and host sharing resources (network, shared folders,
> etc.) and provides a reasonably user friendly interface (in a worst case, a
> script that can encapsulate all of the text commands to the virtualization
> system)?
> Note the host is X86-64, but the guest is IA-32.
> 
> Any assistance (based on "real world" experience) will be appreciated.

I manage three servers using KVM and managed using libvirt (virsh from the
command line or virtual-manager from the GUI).  Currently my bare-metal boxes
run SL6.x, but I'm running a variety of virtual machines (Windows, SL 6 and 7,
CentOS 5).  I have had no particular issues with this setup.  However I am
considering to test out oVirt as an alternative management tool, which also
makes use of KVM and libvirt under the hood.

Two of bare metal boxes have 4 physical NICs each, so I have isolated one NIC
for "management", which means that's the physical network and IP subnet I use
to log into the bare metal via SSH and such.  Then I have configured a bridge
on one of the other interfaces, which the virtual machines uses.  One of the
subnets actually have an external DHCP server, which these virtual machines do
pick up as if it was a physical stand alone machine.

With 802.11, I presume you mean wireless networking.  You can configure that
several ways with libvirt.  If you want the VMs to act/look like as physical
machines on your network, you will need to establish a bridge where the
wireless network is a member.  I have not tested that.

Another approach is to use the built in NAT support which libvirt can
configure automatically.  There you define a libvirt virtual network, with
it's own private network range and decide if this should be NATed or not.  If
your VMs are connected to this network (also configured as a bridge, often
virbr0...).

And you can also play with macvtap as well.  That behaves closer to bridging
with another physical network interface, but without using a bridge.  There
are several pitfalls with this approach, pretty much decided by your needs and
the rest of your network infrastructure.

Performance wise, I am quite satisfied with both bridging and the virtual
network support which is built into libvirt.  One of the sites have actually
virtualized the firewall, even though a native bare-metal firewall would
perform better the virtualized firewall isn't that far away.

It may not be as shiny and polished as VirtualBox or vmware.  But it ships
out-of-the-box on SL5, SL6 and SL7, all you need to do is to 'yum install
libvirt virtual-manager virsh'.  And any management tool supporting libvirt
should be able to manage all the KVM based VMs without much extra hassle.  And
the management tools doesn't necessarily need to run on the bare-metal host
either.  It can run on a completely different machine, just using either SSH
or the libvirt protocol directly.


--
kind regards,

David Sommerseth